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- Oracle DBA Interview Questions and Answers
- Oracle dba interview questions and answers
- Oracle DBA Interview Questions & Answers
Explore Now! These questions and answers are suitable for both freshers and experienced professionals at any level.
Do you like to switch your career? Here's our recommendation on the important things to need to prepare for the job interview to achieve your career goals in an easy way. DBA has the all privileges on the database which usually developers wont have. DBA responsibilities are to install, configure, backup, recover the database. He should have good command on all activities to be done on a database.
Oracle DBA Interview Questions and Answers
There are a lot of opportunities from many reputed companies in the world. According to research, Oracle DBA has a market share of about 0. This course will help you to achieve excellence in this domain. Oracle automatically maintains and uses indexes and when any change is made in the table data Oracle automatically distributes it into relevant indexes.
Oracle usually publishes a major release once a 4 year. This digit is usually followed by a character describing the nature of the release. For example: 9i internet , 10g grid , 11g grid , 12c cloud. Oracle publishes the major release as maintenance release 1 and then usually publishes a second maintenance release during the lifetime of the software.
New features are added to database Software with maintenance releases. This will be o for database software. Patch set updates are published 4 times a year by Oracle and as you apply them to your database software, this fourth digit advances.
A synonym is an identifier that can be used to reference another database object in a SQL statement. The types of database objects for which a synonym may be created are a table, view, sequence, or another synonym. Passwords for database users are stored in the data dictionary of the database. When a user wants to log into the database, the username and password provided by the user are checked against the values stored in the database.
If the username and password match, the user is granted access to the database. The data dictionary is part of the database and it will be accessible as long as the database is open. The passwords for administrators are stored in the dictionary as well. When the database is closed, the data dictionary will be inaccessible. A password file is a separate operating system file that is stored on a disk outside of the database. Administrators who have those privileges are authenticated using this password file even when the database is down.
This may involve installing and configuring a database from scratch. On a running system, the DBA will be the only privileged person who can shut down and startup the database. The DBA will create new users and manage the privileges of each user. He will take regular backups to ensure that data is safe.
In case of a disaster, he will be responsible for restoring the database from backups. He will have to do monitor the space usage and do capacity planning for the database. He will be responsible for enforcing security policies. He will have to monitor database activities. He will have to tune the database so that it works at an acceptable speed. He is expected to follow the latest patches and apply them when applicable. An Oracle developer is mainly responsible for developing backend applications.
They do data modeling according to business rules. The design tables, create indexes and other types of constraints. They develop procedures using this language. However, the Oracle developers are not expected to administer the database software itself. DBAs are not primarily assigned to develop code. According to the structure of the organization, DBAs might also be assigned development tasks or at least assist the developers where necessary.
If you are going to do batch installations, it is best to do it with Oracle Universal Installer in silent mode. For single installations. However, in batch installations, this will take longer. A response file is a plain text file, where options to create a database are stored.
It is possible to create it manually from scratch but that would take longer and would be erroneous. Installation media comes with a template response file.
It is rather easier to customize it manually. This file also contains notes about the parameters. However, the easiest and most reliable way to create a response file is by using Oracle Universal Installer. It is also possible to create a database via an SQL script. In this script I would specify:. The system global area is a shared memory, which means it can be accessed by multiple processes. This holds data that is required by the instance to operate. The background processes are operating system processes and each process has a specific responsibility in the instance.
An Oracle database resides on disk and this is permanent. It is composed of files that are stored on a disk. These files can be categorized into three types:. You can start up a database with three tools. A parameter file holds instance parameters that govern how an instance operates.
In order to start up an instance, Oracle needs to locate this file. SID- is the service identifier of the instance. This is again a server parameter file.
If Oracle cannot find the two files listed above, it will search for this file. This is the last location to search.
You can start up a database with the modes below:. Even if the database is idle, there is no guarantee that the database will not write anything to files during the snapshot. In the default configuration, the Oracle database will not automatically start after the server reboots.
There are two methods to accomplish this:. When a user connects to a database, he sends SQL queries to the database to execute. In shared server architecture, the total memory consumption will be less. However, certain operations like DBA activities can only be performed on a dedicated server. The shared server process monitors the request queue. When they find an incoming request, they execute this SQL query and place the results in the response queue.
The request queue and the response queue reside in the system global area. The dispatcher processes also monitor the response queue. When it receives a result, they deliver the result to the relevant client. In this architecture, there will be multiple shared server processes and dispatcher processes.
There can be multiple database background processes. When a server process wants to update a data block, it reads the block from disk to buffer cache if the block is not already in the cache and then updates the copy in the cache.
We can make use of one or more rows in order to make the index. The index can increase the performance of retrieval and slows down the performance of insertion.
The table is the first level of the physical unit in the database. Oracle uses tables of a database to store data into rows and columns. Views are read-only as well as read-write. The tablespace is a Logical Storage Unit used to group related logical structures together. It is the logical structure where all the objects of the database will be grouped. It also contains the data dictionary table for the whole data.
Each tablespace is divided into one or more data files and one and more tablespace s are created for each database. Materialized views are objects that have reduced sets of information that have been summarized, grouped, or aggregated from base tables. They are typically used in data warehouses or decision support systems.
Synonym types are private and public. A public synonym does not belong to any schema. In other words, when any database user can access it, it is called a public synonym. A private synonym is one that does belong to a specific schema. In other words, when only the owner can access it, it is called a private synonym.
A sequence generates a serial list of unique numbers for numerical columns of database tables. We can use the sequence on columns for data where we want to insert data in a sequential manner.
A database link is a schema object in one database to access objects in another database. When you create a database link with a Public clause it is available for access to all the users. Row Chaining occurs when the row is too large to fit into one data block when it is first inserted. In this case, Oracle stores the data for the row in a chain of data blocks one or more reserved for that segment.
Oracle dba interview questions and answers
Answer: Oracle Database is a relational database management system RDBMS which is used to store and retrieve the large amounts of data. Oracle Database had physical and logical structures. Logical structures and physical structures are separated from each other. Answer :Oracle database is the collection of datafiles,redologs and control files while Oracle instance is the SGA ,processes in the Memory. We can have 1 or more instance serving a oracle database. In Oracle RAC , we have one set of datafiles,control file and redo logs while instance on one ore more boxes accesses the same database. Question 3 What is a Tablespace?
There are a lot of opportunities from many reputed companies in the world. According to research, Oracle DBA has a market share of about 0. This course will help you to achieve excellence in this domain. Oracle automatically maintains and uses indexes and when any change is made in the table data Oracle automatically distributes it into relevant indexes. Oracle usually publishes a major release once a 4 year. This digit is usually followed by a character describing the nature of the release. For example: 9i internet , 10g grid , 11g grid , 12c cloud.
Best Oracle DBA Interview Questions and Answers. Do you believe that you have the right stuff to be a section in the advancement of future.
Oracle DBA Interview Questions & Answers
This list includes characteristics of the Oracle database, roles of a Database Administrator, tools used for administering the Oracle database, comparing a cluster with a grid, the architecture of Oracle Grid Computing, and more. Many organizations are hiring Oracle DBA experts to meet their requirements and the needs and demands of their customers. In case you are looking for Oracle DBA interview questions, this is the correct place for you. What is Oracle? What is an Oracle Database?
Some primary duties include integrating third-party software, migrating data to the cloud and correcting issues that arise during day to day activities. During a DBA interview, employers want to determine if you can satisfy these tasks and help the organization run smoothly. In a DBA interview, you are likely to be asked general questions you would get in other types of interviews to help potential employers get to know your personality and see if you are a good fit for their company.
Questions about DBA experience and background
И теперь - во что просто не верится - какой-то ни о чем не подозревающий канадский турист держит в своих руках ключ к самому мощному шифровальному алгоритму в истории. Сьюзан набрала полные легкие воздуха и задала неизбежный вопрос: - И где же теперь этот канадец. Стратмор нахмурился: - В этом вся проблема. - Офицер полиции этого не знает. - Не имеет понятия. Рассказ канадца показался ему полным абсурдом, и он подумал, что старик еще не отошел от шока или страдает слабоумием.
В Севилье есть больницы получше. - Этот полицейский… - Клушар рассердился. - Он уронил меня с мотоцикла, бросил на улице, залитого кровью, как зарезанную свинью. Я еле добрел. - Он не предложил вам больницы поприличнее.
Предупредить. Он же вас ненавидит. - Он позвонил и предупредил, что заканчивает работу над алгоритмом, создающим абсолютно стойкие шифры. Я ему не поверил. - Но зачем он вам об этом сообщил? - спросила Сьюзан.
Однако в данный момент у него был перерыв и он поглощал пирог с сыром и перцем в круглосуточной столовой АНБ. Джабба собирался взять третий кусок, когда зазвонил мобильный телефон. - Говорите, - сказал он, быстро проглотив пирог. - Джабба, - проворковала женщина в ответ. - Это Мидж.
Что я здесь делаю? - пробормотал. Ответ был очень простым: есть люди, которым не принято отвечать. - Мистер Беккер, - возвестил громкоговоритель.